Integrated circuit devices are widely used in consumer and commercial applications. Many integrated circuit devices include integrated circuit capacitors therein. For example, many memory devices, such as Dynamic Random Access Memory (DRAM) devices, include integrated circuit capacitors. As is well known to those having skill in the art, an integrated circuit capacitor generally includes a first (lower) electrode, a second (upper) electrode and a dielectric therebetween.
As the integration density of integrated circuit devices continues to increase, it may become desirable to increase the capacitance per unit area of an integrated circuit capacitor. As is well known, the capacitance per unit area may be increased by increasing the effective area of the capacitor, by decreasing the thickness of the dielectric, and/or by increasing the dielectric constant of the dielectric material.
Three-dimensional electrode structures, such as cylindrical, finned and/or trench electrode structures have been developed, to thereby increase the effective area of the capacitor per unit area in the integrated circuit substrate. It is also known to form hemispherical grain silicon electrodes, to increase the surface area of an integrated circuit electrode per unit area of the integrated circuit substrate. See, for example, U.S. Pat. Nos. 6,333,227; 6,245,632; 6,238,973; 6,117,692; 6,087,226; 6,077,573; 6,004,858; 5,960,281; 5,885,867 and 5,821,152, all of which are assigned to the assignee of the present invention, the disclosures of all of which are hereby incorporated herein by reference in their entirety as if set forth fully herein.
It may be desirable to use metal as an integrated circuit electrode, such as a lower electrode of an integrated circuit capacitor, rather than silicon or polysilicon. For example, noble metals, such as platinum (Pt), ruthenium (Ru) and/or iridium (Ir) and/or their oxides may be used as an integrated circuit electrode, such as a lower electrode. In particular, ruthenium-based electrodes, including ruthenium oxide-based electrodes, may be etched by oxygen-containing plasma to form a conductive metal oxide layer. Thus, ruthenium-based electrodes may be particularly desirable.
It is known to increase the surface area of noble metal-containing electrodes using high temperature agglomeration, sputtering and/or oxygen plasma treatments. See, for example, Japanese Publication No. 10-270662, published Oct. 9, 1998 to Takeharu entitled Semiconductor Storage Device Having Capacitor and Its Manufacture; Japanese Publication No. 11-121711, published Apr. 30, 1999 to Teruo et al. entitled Manufacture of Capacitor, Manufacture of Semiconductor Device Capacitor and Semiconductor Device Capacitor; and published PCT Publication No. WO 00/13216, published Mar. 9, 2000 to Marsh et al. entitled Capacitors Comprising Roughened Platinum Layers, Methods of Forming Roughened Layers of Platinum and Methods of Forming Capacitors.